When you start FontViewer for the first time after reboot it may take some time to load. This happens for a couple of reasons. The first is that the .Net Framework (which FontViewer uses) can take time to load. In addition, it takes a few moments for FontViewer to gather the list of fonts.

The previous version of FontViewer had a feature to scan the files on your hard drive and tell you which fonts you are actually using. We have removed that from this version of FontViewer for two reasons. First, scanning today's large hard drives can take a long, long time. Secondly, the results of a scan are not accurate.

FontViewer supports TrueType and OpenType fonts. It does not support other types of fonts like bitmap fonts or Type 1 fonts.

FontViewer lists the font families installed in your machine (Arial,
Courier New, Times New Roman, etc). For every font family, it shows the available typefaces (Bold, Italic, etc.) in the tooltip. In some cases, you may find that FontViewer is not listing some fonts or is classifying the fonts in a what appears to be the wrong manner (for example, all Arial typefaces are listed under Arial, while Microsoft Word shows Arial, Arial Black and Arial Narrow). This is due to the fact that the font classification has changed in Windows Presentation Foundation (WPF). WPF retrieves data from the physical font file and tries to match the font family name with the fonts and gets all typefaces for that family, thus grouping the files in a different manner than other applications. If you need more information about the WPF font selection mode, you can refer to
this article.